A technique of wirelessly transferring energy is similar to telecommunication using an antenna in a broad sense. However, when energy is wirelessly transferred within a short distance, since energy is transmitted within a very short distance in a wavelength, energy transmission efficiency, as well as directivity and a radiation pattern, is very significant.
Recently, a technique of transferring a large capacity energy such as charging of an electrical vehicle, as well as a technique of wirelessly (or in a non-contact manner) transferring energy to an electronic product consuming a small amount of power, such as mobile phones, notebook computers, or the like, to operate the product, has come to prominence. Furthermore, various products that can perform both energy transmission and communication are anticipated to be developed in the future. Subsequently, a receiving device that is able to be provided with power from a transmission unit and performs a communication function, even without a power source, is the next generation in electronics, and this will possibly result in a reduction in the size of the receiving device.
US Patent Publication No. 2010/0190436 A1 entitled “Concurrent wireless power transmission and near-field communication” discloses a similar technique of performing both energy transmission and communication. This document proposes a system for performing wireless power transmission and communication.
However, the technique presented in the above document performs communication limited to a near field by using the same frequency as that of wireless power transmission, and uses a low frequency, having disadvantages in that it is very vulnerable to large capacity data transmission.
Thus, a technique which is able to transmit large capacity data with high efficiency while simultaneously performing wireless power transmission and communication is required.